<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>透明背景效果</title>
    <style>
        .background {
            margin: 100px auto;
            width: 780px;
            height: 439px;
            background-image: url('../images/bg.jpg');
            position: relative;
        }

        .content {
            position: absolute;
            width: 400px;
            height: 200px;
            background-color: #fff;
            opacity: 0.4;
            top: 100px;
            left: 190px;
            border-radius: 10px;
            padding: 10px;
            box-shadow: 3px 3px 5px #888;
            -webkit-box-shadow: 3px 3px 5px #888;
        }
    </style>
</head>
<body>
    <div class="background">
        <div class="content">
            Hello Everyone! Hello World! <br>
            Hello Everyone! Hello Html5! <br>
            Hello Everyone! Hello CSS3! <br>
            Hello Everyone! Hello ES6! <br>
            Hello Everyone! Hello NodeJS! <br>
            Hello Everyone! Hello React! <br>
        </div>
    </div>
</body>
</html>